1. Field of the Invention
The invention relates to a pre-installation assembly for a contact arrangement of a sensor assembly.
2. Description of the Prior Art
In German Published Patent Disclosure DE 19917941 A1, a braking device for a vehicle brake system with a contact arrangement for a sensor assembly is disclosed. In the braking device described, the control electronics, to simplify installation, are accommodated in a housing inverted over at least one pressure sensor, and the electrical connection between the pressure sensor and the control electronics is made automatically upon installation via four spring contact pins. In the process, the housing is secured to a hydraulic block of the braking device, into which block at least one pressure sensor is inserted, so that the spring contact pins are braced on their ends with a defined contact pressure between the facing contact faces of the pressure sensor and of the control electronics. The spring contact pins are inserted into guides which are located in an insulation piece, and the spring contact pins each have a contact sleeve with a contact spring located in it and at least one contact tappet axially displaceable in the contact sleeve, which tappet is acted upon by the contact spring, embodied as a compression spring, in the expulsion direction out of the guide sleeve. Between the contact sleeve and the contact tappet, an axial brace is provided, by which the contact tappet is kept in its contact sleeve. This brace comprises a crimped-over peripheral zone on the end of the contact sleeve that a pistonlike thickened portion of the graduatedly offset contact tappet runs up against. In some embodiments of the known spring contact pins, both end regions are formed by a contact tappet, and from opposite directions the contact tappets engage their contact sleeve that forms the middle region of the spring contact pin. Between the thickened ends of the two contact tappets, the helical compression spring guided in the contact sleeve is braced and, when the spring contact pin has not yet been built in, presses the contact tappet into its terminal position in which it is maximally expelled from the contact sleeve. Thus even in the not yet built-in state, the spring contact pin comprising the contact sleeve, contact tappets and contact spring, forms a stably preassembled and thus easily manipulated assembly. The components of the spring contact pin, however, must be manufactured with extreme dimensional stability, to enable ensuring durable, problem-free contact-making. This is especially true when the assembly overall is designed in filigree fashion. As a result, producing the pre-installation assembly comprising the contact sleeve, contact spring and contact tappets is technically complicated as a whole, and even the individual spring contact pin comprising precision components is relatively expensive.
From German Patent Disclosure DE 10244760 A1, a contact arrangement in a pressure sensor assembly is also known, for monitoring pressure in a vehicle brake system. In this arrangement, spring contacts are provided, which comprise solely the spring winding of a wound helical compression spring and are therefore distinguished by a technically simple design. These helical compression springs used as spring contact pins each have two winding sections with different diameters, and the longer winding section, which penetrates guides in support components, has a markedly smaller winding diameter than a winding section that protrudes from the guides. To improve the guidance properties, the spring winding in the longer winding section is wound as a block; as a result, the axial spring load must be exerted solely by the winding section that protrudes from the guide, which to that end must be correspondingly compressed. The assembly process thus requires that outside the guide, there is enough space for supplying the component that is provided with the second contact face, so that the winding section protruding from the guide can be compressed to a suitable extent, thus providing the contact-making. The space required for compressing the winding section is not structurally available in all contact arrangements for sensor assemblies. Also, the contact face for the winding end of the shoulder winding section must be relatively large, which is again not wanted for every application, because it can have an adverse effect on the available space.